move SS-size between 2 sizes

the following SS is the basic..

per Frame:s=if(above((getspec(0.1,0.2,0)),0.4),0.5,0.9); 

s is the size regarding spec, but it's only 0.5 or 0.9
what means, if spec over 0.4 it will be 0.5 else 0.9 but what i want is that if spec is 0 s=1; if spec is 1 s=0; if spec is 0.3 s=0.7; if spec is 0.5 s=0.5 and and and

and i should only say the bandwiths for spec and size

can anyone help?

Well, I don't really use the spec function, but I think this'll work:

s=1-getspec(0.1,0.2,0)

So:

0=1-(1)
.3=1-(.7)
.7=1-(.3)
1=1-(0)

And so on.

thanx, that works...sometimes it's the easyest way, that i don't see ;-)
see how it looks